In order to accommodate the aesthetic needs of a wearer of a hearing aid device, such devices should be as inconspicuous as possible externally on a wearer. Therefore a necessary miniaturization of the hearing aid devices on the one hand, and their optimally diverse range of functions together with high-quality processing, within the hearing aid devices, of the signals that are necessary for improving hearing ability on the other represent opposing requirements.
In addition, the adaptation of hearing aid devices to different types of hearing damage by different power levels and users' demands for the smallest possible designs are forcing manufactures to offer a wide range of hearing aid devices with different sizes for different power ranges.
For reasons of environmental protection and the significant increase in the electrical storage capacity of batteries in recent years, nowadays increasing numbers of hearing aids and hearing aid devices with rechargeable batteries or a rechargeable battery cell are available on the market. These are replacing the previously common zinc-air batteries.
Batteries are in particular suitable for hearing aids with a lower power, such as those used, for example, to improve mild hearing damage and/or with a comparatively small range of functions. It is obviously also possible to use batteries in hearing aid devices with a high amplifier power and/or a wide range of functions. Hereby, it is then preferable to use a plurality of hearing aid devices or a plurality of batteries on an exchange basis.
In particular with ITEs, the requirements relating to miniaturization, the range of functions, amplifier power and battery capacity are particularly high. These rechargeable ITEs are provided with charging contacts for a charger on an identical cover plate for all ITEs of a specific range—which is generally called the faceplate. This is based on the fact that a side of the ITE opposite the cover plate has an otoplastic which has been individually adapted for the hearing aid wearer.
Due to the individual otoplastic design, it makes no sense to attach the charging contacts for the battery on this side of the ITE since then it would generally be necessary also to produce an individually adapted charging cradle for an electrical recharging device. Therefore, in order to be able to operate a plurality of ITEs with a single electrical recharging device, it is necessary to provide the charging contacts on the cover plate.
To remove relatively small ITEs from an ear or an auditory canal of the hearing aid wearer, they have a small thread which may be gripped by the finger of the hearing aid wearer. This thread—also called an extraction or drawing thread—is attached, generally glued, to the side of the cover plate.
In the case of a rechargeable ITE with charging contacts on the side of the cover plate, this thread would be in the way when the ITE is inserted into the charger or in the charging cradle of the charger. In addition, in particular in the case of larger hearing aid devices, such as is the case, for example, with a concha hearing aid device, a thread of this kind can impair the overall aesthetic impression of the hearing aid device.
In addition to the fixed extraction threads known from the prior art, the hearing aid can also be held on an open battery door and pulled out of the human ear thereby.